RSNA and BSTI grading systems of COVID-19 pneumonia: comparison of the diagnostic performance and interobserver agreement

Table 2 Evaluation of agreement between two radiologists in RT-PCR positive and negative patients according to BSTI guidance statement

RT-PCR		BSTI guidance statement		Observer B				Test value Kappa (κ); p
RT-PCR		BSTI guidance statement		1	2	3	4	Test value Kappa (κ); p
Positive	Observer A	1-Classical COVID-19	N %	357 91.5	32 8.2	1 0.3	0	0.707; < 0.001
		2-Probable COVID-19	N %	36 30.0	73 60.8	8 6.7	3 2.5
		3-Indeterminate	N %	0	7 11.7	43 71.7	10 16.7
		4-COVID-19 exclusion	N %	0	0	4 9.5	38 90.5
Negative	Observer A	1-Classical COVID-19	N %	13 100.0	0	0	0	0.645; < 0.001
		2-Probable COVID-19	N %	0	14 82.4	2 11.8	1 5.9
		3-Indeterminate	N %	0	1 2.2	24 53.3	20 44.4
		4-COVID-19 exclusion	N %	0	1 0.5	23 10.6	192 88.9

ISSN: 1471-2342